The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
(1) Field of the Invention
The present invention relates to a nozzle that prevents overflow spills. More particularly, the invention relates to a fuel nozzle system using acoustic signals generated by flowing fuel to shut off the flow of fuel when the resonance of predetermined acoustic signals is acoustically sensed.
(2) Description of the Prior Art
Many current systems that indicate levels in a tank that is being filled are mechanical in nature, i.e., switches are activated by fluid backpressure. Such systems usually work, but not always when the tank is being xe2x80x9ctopped-offxe2x80x9d, and often, spillover of liquid or liquid fuel will occur. Some systems using electrical sensors have the problems associated with calibration, and the complexities of interconnected multiple components raise questions of reliability.
Thus, in accordance with the inventive concept herein, a need has been recognized in the art for a nozzle system for petroleum fuel or other liquids in which the nozzle system uses acoustic signals generated by flowing fuel or the liquid to shut off the flow when the resonance of predetermined acoustic signals is acoustically sensed.
Accordingly, it is a general purpose and primary object of the present invention to provide an acoustic switch that prevents spillover during filling.
It is a further object of the present invention to provide a system for automatically shutting off the flow of liquid into a tank.
It is a still further object of the present invention to provide a fuel nozzle system using acoustic signals generated by flowing liquid fuel to shut off the fuel flow when resonance of predetermined acoustic signals is acoustically sensed.
It is a still further object of the present invention to provide a fuel nozzle system for shutting off the flow of fuel to a tank at selectively different levels.
It is a still further object of the present invention to provide a nozzle system for optically or audibly indicating a predetermined level of fuel in a tank.
It is a still further object of the present invention to provide a system acoustically sensing the level of fuel in a tank for initiating visual and/or optical indicators and shutting off the flow of fuel thereto.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.
To attain the objects described, there is provided a nozzle system for preventing overflow from a tank being filled. In the system, an open-ended elongated tube is disposed in a fuel tank to extend between an opening of the tank at one end and proximate to a bottom of the tank at the other end. A refueling nozzle connected to a source of pressurized fuel or other pressurized liquid has an open end extension to extend through the tank opening and into the elongated tube. The nozzle creates broadband acoustic signals inside of the elongated tube by the turbulent flow of fuel through the nozzle during the filling.
A microphone is mounted on the nozzle near the extension to sense resonant frequency signals of the acoustic signals to generate representative signals. A processing module is connected to the microphone to receive and process the representative signals such that a close signal is generated when the representative signals represent a critical resonant frequency.
The critical resonant frequency is representative of the length of the elongated tube between the opening and the level of fuel in the elongated tube inside of the tank. The critical resonant frequency is predetermined to occur at a level of fuel in the elongate tube corresponding to a full, no-spill level in the tank. A shut-off valve is connected between the fuel source and the nozzle and is responsive to the processing module. The close signal from the processing module closes the flow of pressurized fuel from the source.